The present invention relates to the field of volatile material dispensers. In particular, the present invention is directed to a dispenser and method for controlling the release of volatile materials within a contained environment, such as an automobile, as a function of the ambient temperature within the contained environment.
Many devices have been described that deliver a fragrance, air freshener or the like within a contained environment such as a motor vehicle. One shortcoming of virtually all of such devices is their inability to automatically control the release of the fragrance from the device when the temperature within the vehicle falls or rises as a result of outside temperature changes and sunshine striking the surface of the vehicle.
This shortcoming has been partially addressed in U.S. Pat. No. 5,534,229. The '229 patent teaches the use of a liquid that contains a material that becomes hydrophobic at a specific elevated temperature. This change causes a “clogging” of the wick delivery system that significantly reduces the amount of volatile material released above a specific temperature, above about 122° F. There are several problems with the system disclosed in the '229 patent. First, the system disclosed in the '229 patent does not address the fact that reduced volatile materials are released during times of lower temperatures in the vehicle. Second, the system disclosed in the '229 patent does not account for changes in the release of volatile materials for ambient temperatures under 120° F. Finally, the system disclosed in the '229 patent requires the use of a liquid with a wick for the reduced volatilization to occur. The release of a volatile material from a solid or a gel is not affected by the inclusion of the materials that work in the liquid systems such as the system disclosed in the '229 patent.